/*
 * Copyright 1999-2012 Alibaba Group.
 *  
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *  
 *      http://www.apache.org/licenses/LICENSE-2.0
 *  
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.alibaba.dubbo.governance.sync.util;

import java.util.Map;

public class Pair<K, V> implements Map.Entry<K, V> {

	private K key;

	private V value;
	
	public Pair() {
	}
    
    public Pair(K key, V value) {
        this.key = key;
        this.value = value;
    }

    public K getKey() {
		return key;
	}

	public void setKey(K key) {
		this.key = key;
	}

	public V getValue() {
		return value;
	}

	public V setValue(V value) {
		V old = this.value;
		this.value = value;
		return old;
	}

	@Override
	public int hashCode() {
		final int prime = 31;
		int result = 1;
		result = prime * result + ((key == null) ? 0 : key.hashCode());
		result = prime * result + ((value == null) ? 0 : value.hashCode());
		return result;
	}

	@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (obj == null)
			return false;
		if (getClass() != obj.getClass())
			return false;
		Pair<?, ?> other = (Pair<?, ?>) obj;
		if (key == null) {
			if (other.key != null)
				return false;
		} else if (!key.equals(other.key))
			return false;
		if (value == null) {
			if (other.value != null)
				return false;
		} else if (!value.equals(other.value))
			return false;
		return true;
	}

}